What the two classes are
Florida records a certified air conditioning contractor as CAC and a certified mechanical contractor as CMC, and both appear on this site's air conditioning lists. The codes come from the state's published occupation table for the construction board, not from the letters.
There are registered versions of both, RA and RM. A registered license is issued on the strength of a local authority's licensing rather than the statewide examination, so it travels less far. It is still a license.
A replacement needs a permit
Swapping a whole system is permitted work in all three of the cities on this site, and the permit is pulled by the licensed contractor rather than by you. It is closed out by an inspection.
Ask which office the permit goes through before you sign. Cape Coral runs its own building division, Fort Myers goes through Lee County and Naples goes through Collier County, so a company working all three is dealing with three separate queues.
What a license does not tell you
A license is a floor. It says the holder met the state's requirements and is in good standing today. It says nothing about how a warranty claim gets handled, or whether the technician on your roof works for the license holder.
Ask whose license number goes on the permit. If the answer is not the company you are paying, that is the thing to resolve first.
Running the check yourself
Open the DBPR licensee search, put the company name in the business-name field and read the status line. Every business ranked on this site has its license number printed beside its name, so you can go straight to the number instead.
If the company name returns nothing, search the owner's name. A small shop often holds the license personally.
Do the check before the system fails
Air conditioning is the one trade in this region people hire under pressure. A system that stops cooling in August gets replaced in days, sometimes on the same visit that diagnosed it, and that is the worst moment to be reading a license record for the first time.
Look the number up while the house is still cool. Every business on these pages prints its license number beside its name, so the check takes about a minute and you only have to do it once. Keep the company you checked somewhere you can find it in a hurry.
Questions about this
Does a new air conditioner need a permit in Southwest Florida
A full system replacement is permitted work in Fort Myers, Cape Coral and Naples, and the licensed contractor pulls the permit. Confirm the issuing office with the contractor before work starts.
Is a mechanical contractor the same as an air conditioning contractor
They are two separate certified classes on the state record, CMC and CAC. Both are licensed to work on cooling systems. Read the class on the license rather than assuming from the company name.